Renal microsomal cytochrome P-450 catalyzes the oxygenated metabolism of arachidonic acid to several products that include epoxyeicosatrienoic acids (EETs), W/W-1 alcohols and small amounts of hydroxyeicostetraenoic acids (HETEs). The potent biological activity of some of these metabolite and their potential significance in renal function, makes the characterization of this pathway of arachidonic oxidation important. As part of a multidisciplinary approach to these important questions and, in support of Projects 1-6, Core B will apply standard stablished methods of extraction, purification, HPLC, GC/MS and RIA to the identification and quantification of eicosanoids present in biological samples.